RMS (Root-Mean Square)
It is the minimum continuous sinewave power output measured in watts that can be delivered by the amplifier into a rated load, over the specified bandwidth with maximum specified total harmonic distortion.
PMPO (Peak Music Power Output)
This is the capability of an amplifier either over a short duration during which there is no perceptible sag of the power supplies during the measurement, or when very high-quality power supplies are used with normal music input. It appears that some companies simply multiply RMS output by 8 or (2√2)2 . RMS power is a more relied upon method for comparison.

Even though PMPO is not a well-defined standard of measurement, it is often seen on the product packaging or on the panel of a car audio amplifier (Fig. 1). Different manufacturers use different definitions for this rating. PMPO is more of a marketing tool to attract customers who are looking for a higher power rating with lower cost audio amplifiers.
Unfortunately, that’s a poor example of a PMPO rating. At 12-15v with a 20A fuse, you’ll be lucky for it to peak at 300w, let alone 1000w.
i was taught, if an 2 channel amp is 1000w P.M.P.O. it would be 500w M.P.O. so 250w RMS. split over 2 channels 125w RMS per channel.
I received these 2 amps PA-80D. P.M.P.O 1000W and all that came was the top with all the jacks and knob attached to the circuit board.With a red and black wire hanging out. There is no bottom inclosure to hide the all the internal components. Is that normal and where do the red and black wires connect to?